Thermoformed blister packaging is well-known in the art. The thermoformed blister packages are manufactured using conventional thermoforming processes from conventional clear thermoplastic sheet materials. Numerous types of articles are packaged in blister packages ranging from hardware, such as nails and screws, to medical devices. Blister packaging serves multiple purposes, including holding and retaining articles, as well as allowing the observer to see what the package contains, since the thermoplastic is typically transparent. One type of blister package consists of a thermoformed tray with a non-thermoformed cover, the cover being typically made from paper or plastic. This cover is typically glued or heat bonded to the thermoformed plastic tray. In order to have access to the contents of the package, it is necessary to tear, cut or otherwise remove the cover from the package.
Another type of thermoformed plastic package is a one piece tray and cover assembly. The cover and tray are connected by what is referred to as a living hinge. In order to close this type of package, the cover, which is hinged to the lower tray, is folded, about the hinge, over and onto the lower tray in a clam shell type fashion. In order to secure the top cover to the lower tray, it is typically necessary to weld or bond flanges, extending from the upper and lower trays, to each other using an ultrasonic welding technique which is widely known in the art. Although this type of package will secure its contents, it can be very difficult to open. Typically it is necessary to cut through the welded or bonded flanges in order to access the contents of the container. It is not unusual for the contents of the package to be punctured, cut or otherwise damaged by the cutting instrument.
It is quite common to use thermoformed blister packaging for various types of medical device products. Typically a thermoformed plastic blister tray is utilized to hold the medical device, and the tray is covered with a flat cover made from either plastic or paper. The cover is typically heat sealed to a rim or flange extending from the plastic blister. There are several deficiencies associated with the use of this type of thermoformed blister package for medical devices. One disadvantage, in particular, is that the equipment needed for heat sealing is expensive and time consuming to configure, so that it is difficult to frequently change configurations of the package. Additionally, the heat sealed cover must be carefully applied so that the cover may be removed in the field simply by pulling up on the cover. Improper application of the cover may result in the cover not being openable by pulling, and having to be cut off in order to open the package. Cutting open such a package typically requires using sharp instruments which may damage the medical device contained therein. Finally, the cover of a conventional thermoformed package cannot typically be resealed in the field.
What is needed in this art are new thermoformed blister pack packages which have easily secured covers, which are easily removed by the consumer or user.